Wigan Athletic manager Roberto Martinez has insisted that Ashley Williams would not have deliberately kicked the ball at Robin van Persie's head.

A clearance from Swansea City captain Williams caught Manchester United striker Van Persie from close range while he was on the floor having been fouled during yesterday's match at the Liberty Stadium.

Speaking after the match, United manager Sir Alex Ferguson launched a scathing attack on Williams and claimed that Van Persie could have been killed during the incident.

However, Martinez, who signed Williams during his time in charge of Swansea, is adamant that the Welsh international is not a "nasty footballer".

"I can guarantee you he is not the type who would do that on purpose," he said. "It is an emotional game and it is very unfortunate that it hits Van Persie in a part of the body where he could have been hurt heavily, and you don't want to see that.

"If you see one of your players with a bang on the back of the head it is really dangerous and it can have bad consequences. You can understand that. But from my point of view, I signed Ashley Williams for Swansea and I know his character inside out.

"I can guarantee you without even looking at the incident that he is not a nasty footballer."

Williams has also insisted that he did not intend to make a connection with Van Persie.